The present disclosure relates to input devices, image reading devices, and image forming apparatuses.
Some image forming apparatuses perform authentication of a user with a personal identification number input by the user when the user executes copying or scanning. Image forming apparatuses are often installed at a location exposed to many eyes. Therefore, the risk is high that the personal identification number is revealed by a third party from the hand movement for entering the personal identification number. To reduce the risk of the personal identification number being revealed by a third party, some devices for inputting personal identification numbers randomly alter the display positions of the numeric keys of a ten-keypad on the input screen.